Im afraid i could have a gap in my technology sequence now if i continue to play
No problem with the savegame in general, continue playing.
You cannot research the 'alien propulsion' tech because you don't have any at your research bases. If you transfer the one from Solidarity to Wisdom for example, the research will show up and the mail will be readable.
It is obviously a bug around the techmail ofc.
Please upload the first save so I can investigate why does it show up with no description.
-geever